Piano keyboard



FIG. 1 is a perspective view of a Piano Keyboard showing our new design;

FIG. 2 is a perspective view thereof, showing a portable electronic device docked in the cradle;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a front elevational view thereof;

FIG. 7 is a right side elevational view thereof; and,

FIG. 8 is a left side elevational view thereof.

The broken line showings of the portable electronic device in FIG. 2, connectors, feet, and access hatches are included for the purpose of illustrating environment and forms no part of the claimed design. 

The ornamental design for a piano keyboard, as shown and described. 